A demonstrator is arrested by a riot police during a protest in Rio de Janeiro. Brazil's biggest protests in two decades have intensified despite government concessions meant to quell the demonstrations, as 300,000 people took to the streets of Rio de Janeiro and hundreds of thousands more flooded other cities. Photograph: Sergio Moraes/Reuters

Demonstrators fight during a protest against the Confederations Cup and President Dilma Rousseff's government in Recife City June 20, 2013. The demonstrators were fighting after a group tried to stop several fellow protesters from vandalising property and throwing rocks at policemen. Photograph: Marcos Brindicci/Reuters

Rio police protect City Hall from demonstrators during a protest in Belem, at the mouth of the Amazon River. Police and protesters fought in the streets into the early hours today as an estimated one million Brazilians swarmed through more than 80 towns and cities in the biggest demonstrations yet against a government viewed as corrupt at all levels and unresponsive to its people. Photograph: Paulo Santos/Reuters

A demonstrator chases vandals in Recife City. At least one protester was killed in Sao Paulo state when a car rammed into a crowd of demonstrators, after the driver apparently became enraged about being unable to drive along a street. Photograph: Ricardo Moraes/Reuters

A demonstrator tries to stop the riot police in Rio de Janeiro. Peaceful protesters were caught up in the fray as police fired tear gas canisters into their midst and at times indiscriminately used pepper spray. Photograph: Sergio Moraes/Reuters

Demonstrators march through a main street during a protest against the Confederations Cup and the government of Brazil's President Dilma Rousseff in Recife city. The protests took place a week after a violent police crackdown on a much smaller demonstration complaining about an increase in bus and subway fares in Sao Paulo galvanised Brazilians to take their grievances to the streets. Photograph: Ivan Alvarado/Reuters

Demonstrators participate in an anti-government protest in Sao Jose dos Campos. The signs read, "Brazil shows its face" and "It's not difficult to fight for what we want, it is to give up what we love, Brazil." Photograph: Roosevelt Cassio/Reuters

A riot policeman fires his weapon while confronting stone-throwing demonstrators during an anti-government protest in Belem. Photograph: Ney Macondes/Reuters

Police take up position against demonstrators in Belem.The protests come one month before Pope Francis is scheduled to visit Brazil, and ahead of the 2014 World Cup and 2016 Olympics, raising concerns about how Brazilian officials will provide security. Photograph: Ney Macondes/Reuters

A demonstrator offers a flower to a riot policeman during an anti-government protest in Porto Alegre, southern Brazil. Photograph: Gustavo Vara/Reuters